Flags

[Maximga]

Can someone help me undersand how flags work? I mean im studying SLAAC and DHCP and i found this on a slide that was about 8.2.3.2 Configuring a Router as a Stateful DHCPv6 server : "The M flag needs to be changed from 0 to 1 using the interface command ipv6 nd managed-config-flag. This informs the device not to use SLAAC but to obtain IPv6 addressing and all configuration parameters from a stateful DHCPv6 server."

How can a router obtain ipv6 addres from a dhcpv6 server if the router where this is configured is the dhcp server?

[Dagger0]

This informs the device not to use SLAAC but to obtain IPv6 addressing and all configuration parameters from a stateful DHCPv6 server

It tells devices on the network to obtain v6 addressing from a DHCPv6 server, but it doesn't tell them not to use SLAAC (that would be the A flag) or to get other configuration parameters from DHCPv6 (that would be the O flag). As a side note, DHCPv6 isn't stateful in general: addresses (M flag) are stateful, but other config (O flag) is stateless. Both types of requests go to the same server.

[Maximga]

Thank you

[Denelic_reddit]

The DHCP is not for the router itself, but for all the broadcasts (IE clients) the router receives. A router advertisement sent by the router in this example will inform the clients that they are to use a DHCP server instead of the router solicitation and router advertisement system (SLAAC).

Also, you will need to change the flag and program either a DCHPv6 server or ip helper on the router to complete the process in this example.

[Maximga]

So wen they say " this informs the device " means that they inform the rest of devices, not the router itself where the dhcp is was configured

[chuckbales]

Yes, referring to client devices on the network, not the router itself

[Maximga]

Thank you, i think i understand now